Re: [PATCH v8 3/8] xen/arm: return int *_dcache_va_range

[Ian Campbell <Ian.Campbell@citrix.com>]

On Mon, 2014-10-20 at 10:48 +0100, Stefano Stabellini wrote:
> These functions cannot really fail on ARM, but their x86 equivalents can
> (-EOPNOTSUPP). Change the prototype to return int.

The subject seems to be missing a word (from?), or is somehow garbled.


> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Reviewed-by: Julien Grall <julien.grall@linaro.org>
> 
> ---
> 
> Changes in v6:
> - do not return int from flush_page_to_ram.
> ---
>  xen/arch/arm/mm.c          |    2 +-
>  xen/include/asm-arm/page.h |    6 ++++--
>  2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index e43499a..8e989bf 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -388,7 +388,7 @@ void flush_page_to_ram(unsigned long mfn)
>  {
>      void *v = map_domain_page(mfn);
>  
> -    clean_and_invalidate_dcache_va_range(v, PAGE_SIZE);
> +    ASSERT(clean_and_invalidate_dcache_va_range(v, PAGE_SIZE) == 0);

Just this one assert? What about all the other callers of
*_dcache_va_range?



>      unmap_domain_page(v);
>  }
>  
> diff --git a/xen/include/asm-arm/page.h b/xen/include/asm-arm/page.h
> index 1327b00..26c5856 100644
> --- a/xen/include/asm-arm/page.h
> +++ b/xen/include/asm-arm/page.h
> @@ -268,16 +268,17 @@ extern size_t cacheline_bytes;
>  /* Functions for flushing medium-sized areas.
>   * if 'range' is large enough we might want to use model-specific
>   * full-cache flushes. */
> -static inline void clean_dcache_va_range(const void *p, unsigned long size)
> +static inline int clean_dcache_va_range(const void *p, unsigned long size)
>  {
>      const void *end;
>      dsb(sy);           /* So the CPU issues all writes to the range */
>      for ( end = p + size; p < end; p += cacheline_bytes )
>          asm volatile (__clean_dcache_one(0) : : "r" (p));
>      dsb(sy);           /* So we know the flushes happen before continuing */
> +    return 0;
>  }
>  
> -static inline void clean_and_invalidate_dcache_va_range
> +static inline int clean_and_invalidate_dcache_va_range
>      (const void *p, unsigned long size)
>  {
>      const void *end;
> @@ -285,6 +286,7 @@ static inline void clean_and_invalidate_dcache_va_range
>      for ( end = p + size; p < end; p += cacheline_bytes )
>          asm volatile (__clean_and_invalidate_dcache_one(0) : : "r" (p));
>      dsb(sy);         /* So we know the flushes happen before continuing */
> +    return 0;
>  }
>  
>  /* Macros for flushing a single small item.  The predicate is always